Process for the preparation of tablets of derivatives of cephalosporanic acid by direct compression

Abstract

The present invention relates to a pharmaceutical form based on cephalosporin. It relates in particularly to a tabletted pharmaceutical form.

We claim: 
     
       1. A dry process for the preparation of tablets of 7-acylaminocephalosporanic acid comprising carrying out a direct compression of a mixture comprising said acid and at least one pharmaceutical excipient, said acid comprising at least about 25% by weight of said mixture and wherein the 7-acylaminocephalosporanic acid has a particle size distribution such that: fewer than 5% of particles have a diameter greater than 250μ,   between 55 and 95% of the particles have a diameter of between 250 and 90μN, and   between 5 and 40% of the particles have a diameter smaller than 90μ.   
     
     
       2. Process of preparation according to claim 1, wherein the mixture employed for the direct compression contains 30 to 70% by weight of the said acid relative to the weight of the final tablet. 
     
     
       3. Process according to claim 1, wherein the 7-acylaminocephalosporanic acid has a relative density of between 0.6 and 0.9. 
     
     
       4. Process according to claim 1, wherein the 7-acylaminocephalosporanic acid derivative is a derivative of 7-acylamino-3-vinylcephalosporanic acid. 
     
     
       5. A process according to claim 1, wherein the excipients are selected from the group consisting of calcium carbonates, calcium phosphates, calcium sulphates, microcrystalline celluloses, cellulose powders, fructoses lactoses, mannitols, sorbitols, starches, pregelled starches and sugars. 
     
     
       6. Process according to claim 5, wherein a lubricating agent chosen from magnesium stearate, stearic acid, talc and a polyethylene glycol is added. 
     
     
       7. Tablets of derivatives of 7-acylaminocephalosporanic acid prepared using the process according to claim 1.